Question

I have a function which calculates the mean of a list passed as an argument. I would like to know which of Java exception should I throw when I try to compute the mean of a list of size 0.

public double mean (MyLinkedList<? extends Number> list)
{
    if (list.isEmpty())
        throw new ????????; //If I am not mistaken Java has some defined exception for this case

    //code goes here
}

Thanks.

Answer 1

You can throw a new IllegalArgumentException().

Thrown to indicate that a method has been passed an illegal or inappropriate argument.

Just don’t forget to pass a clear message as a first argument. This will really help you to understand what happend.

For example “Can’t use mean on an empty List”.